The present invention relates to a toothbrush and, in particular to a toothbrush for efficiently removing plaque from teeth, and for facilitating gingival tissue stimulation.
Teeth are necessary for the mastication of food and for assisting with the formation of speech. In order for the teeth to perform their function over a long period of time, it is desirable for them to be cleaned by brushing on a regular basis in order to prevent plaque and calculus from being deposited on the crowns and roots of teeth, and thus provide protection against periodontal disease and tooth decay. Brushing also aids in maintaining healthy gums by stimulation of the gingival tissue which helps to maintain healthy supporting bone.
For brushing teeth, it has heretofore been customary to use standard toothbrushes having xe2x80x9ctuftsxe2x80x9d of bristle assemblies planted on one face of one end of toothbrush handle. Additionally, electric toothbrushes, or toothbrushes powered by other means, such as water, have been developed in recent years that have also been widely used. The prior art manual or powered toothbrushes provide a variety of bristle sizes, shapes and configurations. By correct manipulation of the manual or powered toothbrush, the top and sides of the tooth, and the opening to the gingival crevice can be cleaned.
However, proper manipulation of the toothbrush is not always easy for most people, particularly, in the situation where the user is elderly, infirmed, disabled, or in the situation where the user is someone whose fine motor skills are either not fully developed, or are diminished. Further, manipulation of the toothbrush is not always easy where a persons"" teeth are brushed by a second party due to the inability of the person to clean their own teeth. Under these circumstances, manipulation of the toothbrush to provide adequate cleaning of the teeth and stimulation of the gingival tissue can be difficult.
Improper manipulation of the brush can also adversely affect the health of the teeth and gums. The area of the tooth where the crown and root meet is referred to as the cemento-enamel junction. The root of the tooth is covered by cementum; a material which is softer than xe2x80x9cenamelxe2x80x9d, and which is easily abraded by horizontal scrubbing. The areas of abrasion and recession caused by horizontal scrubbing extend through the cementum into the underlying dentin causing hypersensitivity and leaving the root areas much more prone to decay. In addition, fibres from the gum tissue which are attached to the cementum are brushed away and can not be reattached. Damage to both the root structure and the gum tissue is irreversible.
Correct brushing techniques with manual toothbrushes are extremely difficult to teach to the vast majority of people. Further, as a result of sheer frustration, most people will usually revert to horizontal scrubbing on the sides of their teeth. While this motion is acceptable if the user is brushing the harder, biting surfaces of the tooth, it is not advisable at the gum level for the reasons stated hereinabove.
In order to address these problems, a wide variety of manual toothbrushes and powered toothbrushes have been previously proposed. Some of these are described hereinbelow.
U.S. Pat. No. 5,842,249 (Sato) describes a toothbrush having a two or three sided channel (e.g. xe2x80x9cU-shapedxe2x80x9d) with bristles on all interior surfaces of the channel. As the brush is moved over the teeth, the bristles clean both the internal and external sides, or the top and both sides, of the tooth. The configuration of the bristles is set so as to improve the efficiency of brushing of either the front teeth or the molar teeth.
Similar xe2x80x9cchannelxe2x80x9d type toothbrushes are described in numerous patents including, for example, U.S. Pat. No. 887,181, U.S. Pat. No. 1,707,118, U.S. Pat. No. 2,066,241, U.S. Pat. No. 2,093,383, U.S. Pat. No. 2,771,624, U.S. Pat. No. 3,065,479, U.S. Pat. No. 4,757,570 and U.S. Pat. No. 5,137,039. In all of these patents the bristles are essentially fixed and cleaning of the teeth is accomplished by pulling the brush over the teeth.
U.S. Pat. No. 4,223,417 (Solow) also provides a xe2x80x9cU-shapedxe2x80x9d toothbrush. In this device, however, the side brushes are powered so as to vibrate in an up and down fashion in order to loosen materials at the gum line.
U.S. Pat. No. 5,142,724 (Park) describes a self-powered toothbrush with a rotary head which rotates on the surfaces of the tooth. A single rotary brush is described, which rotates about an axis perpendicular to the surface of the tooth being cleaned. Rotation of the brush is achieved by the difference pressures exerted on the brush surface as it is pulled along the surface of the tooth. Dame, in U.S. Pat. No. 6,256,826 provides an improved version of this toothbrush, which rotates more readily.
U.S. Pat. No. 5,276,932 (Byrd) describes a toothbrush having two rotary brushes powered by a mechanical linkage to a actuator located on the toothbrush handle. Again, however, the brushes both rotate about an axis located perpendicular to the surface of the tooth.
U.S. Pat. No. 5,115,530 (Distiso) describes an alternative arrangement for a toothbrush wherein a long bristle section is rotated about an axis which is parallel to the face of the tooth surface, and parallel to the gum line of the teeth being clean. Accordingly, the bristles move up or down the surface of the tooth.
U.S. Pat. No. 5,177,826 (Vrignaud et al.) describe a U-shaped toothbrush wherein the brushes located on the sides of the brush head both rotate. In this embodiment, the brushes both rotate about an axis which is perpendicular to the surface of the tooth being cleaned so that the brushes rotate around on the surface of the tooth. U.S. Pat. No. 4,766,630 (Hegemann) provides a similar device.
While these devices have met with limited success, it would be desirable to provide an improved toothbrush which provides for improved plaque removal and stimulation of the gingival tissue, particularly, for those people who have difficulty in the normal manipulation of a standard toothbrush.
Accordingly, it is a first object of the present invention to provide a toothbrush which provides improved cleansing of the portion of the tooth adjacent to the gingival tissue.
It is a further object of the present invention to provide a toothbrush which provides effective cleaning of the teeth and stimulation of the gingival tissue, particularly in the area adjacent to the opening to the gingival crevice.
It is a still further object of the present invention to provide a toothbrush which provides effective cleansing of the teeth for anyone, but particularly for those who have difficulty in manipulation of a standard toothbrush.
These and other objects are either fully or partially attained by providing a toothbrush having a generally U-shaped head with rotating brushes located on the sides of the toothbrush head, wherein the brushes rotate about an axis which axis is essentially parallel to the long axis of the tooth, and also with bristles essentially perpendicular to the buccal (facial) and lingual surfaces, of the teeth being cleaned.
Accordingly, the present invention provides a toothbrush comprising:
an elongated handle; and
a brush head section, and preferably a U-shaped brush head section,
wherein said brush head section comprises:
a main head section,
a rotary brush located on each side of the main head section adapted to be located, in use, on the buccal and lingual side of a tooth to be cleaned; and
an axle for each rotary brush wherein said axle connects said rotary brush to said main head section;
characterized in that each of said rotary brushes rotates about said axle so that the axis of rotation of each brush is essentially parallel to the long axis of the tooth.
The axis of rotation of each brush is, in use, located on the lingual and buccal side of the teeth, and is therefore, the bristles of the rotary brushes are essentially perpendicular to the buccal and lingual surfaces of the teeth being cleaned. The xe2x80x9clong axis of the toothxe2x80x9d is generally, the axis of the tooth which runs from the centre of the root structure, to the centre of the biting surface of the tooth, and is essentially the centre line of the tooth. Accordingly the long axis of the tooth runs vertically from the tip of the root structure to the centre of the biting surface of the tooth.
Additionally, the toothbrush can additionally comprise a third brush to cleanse the biting surface of the tooth, where horizontal scrubbing, in this application, is permissible.
The brushes are preferably held in contact with the tooth and gum tissue by a biasing means, such as, for example, a spring or by a resilient section of the axle or main head section. This can allow the brush to be used to clean teeth of different width, such as, for example, cleaning either the incisors, cuspids, or molar teeth since the biasing means would automatically adjust to the different tooth widths.
While the rotary action of the rotary brushes might be provided or assisted by an external power source, such as an electric motor, water or air pressure, or by a mechanical actuating device, preferably, the brushes rotate as a result of the pushing or pulling, horizontal, longitudinal movement of the brush head along the line of teeth to be cleaned. Accordingly, the brush is preferably a non-electrically and/or non-mechanically powered brush. This is accomplished by providing a brush which contacts the tooth, at rest, and which can freely rotate about its axle so that linear movement of the brush head causes the brush to rotate.
It is also preferred that the resiliency of the bristles of the brush, and/or the biasing means used be such that the brushes are normally held in contact with the teeth.